Many small machine tools, hand tools and portable power tools use the well-known Jacobs chuck to clamp a tool spindle in the tool. The key of a Jacobs chuck is often lost between uses of the tool because few such tools have a satisfactory means for storing the key.
One type of solution to the problem has been to provide means to mount the key on the hand tool or on the power cord close to the hand tool. Holloway U.S. Pat. No. 1,821,436 shows such a solution to the problem. It has also been known to provide a rubber "bracket" which fastens onto the power cord and has jaws which frictionally grip the shank of the chuck key. The difficulty with such devices is that the person using the hand tool must still remember to put the chuck key back where it belongs.
Another type of solution to the chuck key problem is to provide means for permanently mounting the chuck key on the hand tool in such a way that it may be selectively engaged and disengaged with the ring gear of the chuck. The only such arrangements known to applicant are disclosed in Kurtovich U.S. Pat. No. 2,807,732, Lucarelli U.S. Pat. No. 3,174,365, and Gage U.S. Pat. No. 3,728,038. These patents eliminate the lost key problem, but require either a complete redesign of the tool housing, as in Kurtovich; or store the key in a location where it may interfere with use of the tool as in Lucarelli and Gage.